Butterfly valve body

ABSTRACT

A butterfly valve body comprising an annular gasket defining a valve disc seat which is disposed in an annular groove. The gasket is formed of a resilient material and is proportioned to provide an annular space in the groove. The butterfly valve body further includes an annular retaining ring disposed within the annular space, the ring being split. The ring may be displaced at the split for insertion into the annular space. Means are provided for precluding axial movement of the ring in a direction away from the gasket so as to prevent rocking of portions of the ring.

United States Patent [1 1 Crookham et al. v i

[ Nov. 27, 1973 BUTTERFLY VALVE BODY [75] lnventors: Carter C. Crookham;Robert C.

Billings, both of Oskaloosa, Iowa 3,412,975 11/1968 Kurkjian 251/307 XPrimary Examinerl-lenry T. Klinksiek Attorney-William E. Anderson et a1.

[5 7 ABSTRACT A butterfly valve body comprising an annular gasketdefining a valve disc seat which is disposed in an annular groove. Thegasket is formed of a resilient material ((51. 25ll3fllzi62r8iggg and isproportioned to provide an annular Space in the [58] Field O t s eQ ciiIKIIIII..QIIIIIE I7/1s7 1ss- The butterfly valve body includes 251/306285/356 annular retaining ring disposed within the annular space, thering being split. The ring may be displaced [56] References Cited at thesplit for insertion into the annular space. Means are provided forprecluding axial movement of the UNITED STATES PATENTS ring in adirection away from the gasket so as to prevent rocking of portions ofthe ring 3,197,174 7/1965 Killian 3,393,697 7/1968 Fawkes 251/307 X 20Claims, 9 Drawing Figures 45 i a 1 i i I: 70 3 1/ i I LJ- 1PATENIEDNDVZTIHH 3,774,880

SHEET 2.0F 2

F164 F 64 F1656 BUTTERFLY VALVE BODY The present invention relates tobutterfly valves and, more particularly, to butterfly valves whichinclude a resilient gasket defining a valve seat adapted to cooperatewith the periphery of a valve disc to provide a seal.

Butterfly valves conventionally include a valve body defining a fluidflow passageway, and a circular or generally circular valve disc mountedwithin the passageway for pivotal movement between an open positionparallel to the longitudinal axis of the flow passageway and a closedposition perpendicular to the longitudinal axis of the flow passageway.When in the closed position, a peripheral portion of the disc engages aseat defined within the valve body to provide a fluid-tight seal. One ofthe interchanging sealing surfaces of the disc and seat is preferablydefined by a resilient material forming a gasket to assure a tight fitbetween these surfaces. In addition, theposition of one of the surfacesis desirably rendered adjustable to eliminate the necessity of precisemachiningwhen the valve is fabricated and to permit compensation forwear and other factors adverse to a fluid-tight seal after the valve hasbeen placed in service.

One approach for achieving the desired surface adjustment is to providemeans for compressing the resilient material or gasket which defines oneof the interengaging sealing surfaces so as to expand the material andthereby shift the position of the sealing surface. More specifically, acommon approach has been to providean annular gasket of rubber orelastomeric ma- 1 terial disposed in a groove in the valve body, theinner periphery of the gasket defining a seat for engagement by theouter periphery of a valve disc. Means are then provided for applyingaxially directed force to the annular gasket to expand it radially asnecessary to achieve the desired sealing relationship.

In the past, the annular gasket has been positioned within a groove ofthe valve body with one of its circular or end faces abutting one wallof the groove and with the other of its end faces engaged by a series ofmetal segmentsarranged within the groove to form a segmented ring..Means were provided for urging the segments into pressure engagementwith the gasket. This approach has not been completely satisfactorysince the segments tend to tip or roll away from the gasket so as toreduce their effectiveness. Solid rings in place of the segments havebeen proposed, but such rings require a sepcializedmachining of thevalve body to permit their insertion behind the gasket.

Accordingly, it is the principal object of the present invention toprovide an improved butterfly valve of the type which includes a valvedisc seat defined by a resilient material and means for placing theresilient material in compression so as to shift the position of thevalve seat.

Other objects and advantages of the invention will become apparent withreference to the following description and the accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary elevational view, partially in section, of abutterfly valve showing various of the features of the invention;

FIG. 2 is an enlarged fragmentary sectional elevational view of aportion of the butterfly valve shown in FIG. 1;

FIG. 3 is an enlarged fragmentary plan view of that portion of thebutterfly valve of FIG. 1 which is shown in FIG. 2;

FIGS. 4 and 5 are enlarged plan and elevational views, respectively, ofone element forming a portion of the butterfly valve shown in FIGS. 1through 3;

F lG. 6 is an elevational view on a reduced scale of another elementforming a portion of the butterfly valve shown in FIGS. 1 through 3;

FIG. 7 is a perspective view of the element shown in FIG. 6, but in apartially collapsed condition; and

FIGS. 8 and 9 are elevational views showing alternate forms of theelement illustrated in FIG. 6.

Referring more specifically to the drawings, there is illustrated inFIG. 1 a butterfly valve 10 which incorporates various of the featuresof the invention. The valve 10 includes a valve body 12, onlya portionof which ;is illustrated. Basically, the valve body includes a generallycylindrical wall 14 defining a fluid flow passageway 16, thelongitudinal axis of this passageway beinghereinafter referred to as theflow axis of the passageway. Although not shown in the drawing, itiscontemplated that an annular flange or other means be provided at eachend of the cylindrical wall 14 to facilitate attachmentof the valvebodyto suitable segments of,pipe or conduit.

Projecting from the valve body at diametrically opposed locations are apair of trunnions 18 which define suitable journals for a valve stem 20.Although all of the internal detals of construction of the trunnions arenot shown, each journal is illustrated as being lined with a suitablebearing material indicated at 22, and each may be provided with asealing element such as an O-ring 24 disposed in a suitable'groove, asshown, or. in the bearing space. One end 26 of the valve stem 20projects outwardly of its trunnion 18 for connection to a suitableoperating device (not shown) by means of which rotation of the stem iseffected.

. A valve disc 28 is mounted on the valve stem and, as illustrated, iscylindrical and includes a diametrical bore to receive the vale stem20.I-lowever, the disc may be provided with diametrically opposed flatsunder some circumstances at the points where the valve stem is joined tothe disc. Suitable holes extend through the disc and stem to receivepins 30 by means of which the disc is secured to the stem, but the discmay also: be keyed or otherwise held to the stem. The disc includesadjacent one face a radially projecting peripheral flange 32, the edgeof which engages a valve seat 34 defined by a gasket 36, soon to bedescribedThe plane within which the edge of the valve disc lies isoffset from the axis of rotation of the disc, as defined by thelongitudinal axis of the valve stem 20, to make possible 360 contactbetween the edge and the valve seat;i3,4.

In order to accommodate the gasket 36, the valve body 12 is providedwith an inner annular groove 38, in the surface of the cylindrical wall14 which defines the fluid flow passageway 16. The groove is positionedso as to be intersected by the plane defined by the edge of the valvedisc flange 32 when the disc is in the closed position transverse to thefluid flow passageway and includes a base 40 and opposed side walls 42and 44. The base 40 may define a generally cylindrical surface, and isso illustrated, while the side walls42and44 have a specificconfiguration (FIG. 2). More specifically, the groove wall 42 nearestthe valve stem 20,,hereinafter sometimes referred to as the left wallbecause of its lo cation in the drawing, is formedto provide an undercut46 relative to which an annular lip 48 is disposed in overhangingrelation. The opposite or right wall 44 of the groove 38 lies generallyin a plane normal to the flow axis of the valve body and is providedwith an annular projection 50, the lower surface of which is spaced fromthe base 40 of the groove.

The valve seat 34 is defined by the inner surface of the annular gasket36 which is formed of a resilient elastomeric material such as rubberwhich will expand under compression if otherwise unrestrained. Variousmaterials known in the art for this particular application are suitable.The gasket 36 may be formed of one piece, as shown, of two or morepieces, which pieces may or may not be connected or bonded to oneanother at their adjacent ends. It is formed to provide a pair ofaxially extending annular flanges 54 and 56 adjacent its outer periphery(FIG. 2), and extends radially from these flanges a distance greaterthan the depth of the groove 38 so that the seat 34 defined by the innersurface of the gasket 36 is disposed inwardly of the inner surface ofthe valve body walls defining the fluid flow passageway 16. As shown,the gasket is of a lesser axial width than the groove 38, i.e., theaxial width of the gasket at its outer surface defined by the flanges 54and 56 is less than the axial width of the base 40 of the groove.However, the flanges 54 and 56 could extend from the wall 44 to the wall46 of the groove if desired. The seat 34 itself may define a cylindricalsurface but, as shown, is inclined slightly relative to the flow axisand therefore defines a frustoconical surface to enhance the sealingability of the valve. The leading and trailing edges of the gasket arechamfered adjacent the seat 34, as at 58. I

As disposed in the groove 38, the outer surface of the gasket 36 restson the base 40 of the groove, with the flange 54 of the gasket disposedwithin the undercut 46 of the groove wall 42,. thereby serving to lockthe flange 54-within the groove. Preferably, the groove wall 42 and theadjacent face of the gasket 36 are so shaped as topermit intimateengagement between the wall and gasket, and in the illustratedembodiment, the edges of each are rounded to eliminate stressconcentrations. Because of the difference between the axial width of thegasket and the axial width of the groove, an annular space is providedbetween the opposite face of the gasket (i.e., the face on the right inFIGS. 1 and 2) and the wall 44 of the groove.

With the gasket supported on the base 40 of the groove with one facethereof in abutting intimate engagement with the wall 48 of the groove,compressive forces applied to the opposite face of the gasket,particularly those forces having an axial component, will cause radialinward expansion of the gasket effective to vary the position of thevalve seat 34. Such compressive forces are applied to the gasket bymeans which include, in the illustrated embodiment, a retaining ring 62and a plurality of checks 64. The retaining ring 62 is disposed withinthe groove 38 between the gasket 36 and the groove wall 44 with one facethereof in abutting relation to the gasket. The checks 64 are wedgedintermediate the ring 62 and the groove wall 44 and maintain theretaining ring in axially directed pressure engagement with the gasket.The effective width of the chock and, hence,.the pressure exerted on thegasket 36, may be varied by varying the disposition of the checksrelative to the ring 62.

More specifically, the retaining ring 62 of the illustrated embodimentis circular in shape and is continuous except for a split or cut 66which is V-shaped in cross section as viewed in a plane normal totheflow axis of the valve body (FIG. 6). The ends of the ring thereforeinterlock to prevent shifting movement thereof relative to each other inradial directions. The outer diameter of the ring is slightly less thanthe diameter of the cylindrical surface defining the base 40 of thegroove 38 and, as shown in the drawings, is greater than the diameter ofthe flow passageway of the valve body adjacent the groove (FIG. 2).

The ring is preferably formed of a metal which is resistant to corrosionfrom exposure to the fluid being conveyed, and should be resilient ordeformable so that the ring can be collapsed for insertion into thegroove 38. This can be done, for example, by taking the ends of the ringat the split 66, displacing them out of alignment, and then overlappingthe ends by squeezing the ring to reduce its outer diameter (FIG. 7). Ifthe ring is formed of a sufficiently resilient material, it will springback into its original shape when the forces on it are released.Otherwise, it can be urged back into its original shape manually.

That face of the ring which engages the gasket 36, the left face of thering in FIG. 2, is shaped to conform intimately to the right face of thegasket over a surface of the gasket extending from adjacent the innersurface or seat 34 of the gasket to closely adjacent the base 40 of thegroove. The gasket is thus engaged and contained over essentially itsentire lateral surfaces by the side wall 42 of the groove and by theretaining ring 62, and is engaged and contained over its outercylindrical surface by the bottom wall 40 of the groove. Any axiallydirected forces exerted on the gasket by the retaining ring willtherefore cause the seat 34 to be displaced radially inwardly in thedirection of the flow axis of the valve body since this is the onlydirection in which the gasket is not restrained.

It will be noted from FIG. 2 that the retaining ring 62 is provided withan annular lip 68 which overlies the inner surface of the annular flange56 of the gasket 36. In a preferred embodiment, the retaining ring isdimensioned so that the outer surface 70 of the lip will exert aradially directed outward force on the flange 56 when the ends of thering are in abutting relation at the split 66. That is, the outerdiameter of the lip 68, as defined by the surface 70, is greater thanthe inner diameter of the flange 56 in the uncompressed state. In orderfor the ring to exert a radially directed outward force on the flange56, it is forced into a circular configuration within the groove 38against the flange 56 by forcefully expanding it until the ends of thering abut at the split 66. The V-shaped configuration of the ring endsat the split, plus the resiliency of the ring tending to force the endsinto engagement with each other, maintains the ring in the expandedcondition. This condition is also maintained by the ring, when instress, to create the seat. The flange 56 of the gasket and the ring 62are thus in compression, and the gasket and ring are held securely inplace.

Alternatively, the ring 62 may be dimensioned so as not to be incompression after initial installation of the ring and so as not toplace the flange 56 in radial compression. Under such conditions, theremight conceivably be a slight gap between the ends of the ring at thesplit 66. However, the fact that the ring is continuous except for thesplit 66 minimizes any tipping or rocking tion since all portions areinterconnected to each other,

the ring being a single piece. More specifically, in order for any oneportion of the ring to tip or rock, as about a point along the right endedge of the ring so as to lift the surface 70 of the lip 68 off theflange 56 of the gasket, it would be necessary for a connected portionof the ring to move axially in a direction away from the gasket 36, andsuch axial movement is precluded by the chocks 64, which arecircumferentially spaced around the ring 62, as hereinafter described.The stiffness of the ring also minimizes any tipping or rocking, andaccordingly, the ring should have sufficient stiffness so that it doesnot bend or twist.

Theouter surface of the ring 62 is provided with an annular rib 72 whilethe inner surface 74 is generally flat. Both surfaces converge toward arearward face or edge 76, the configuration of which can best be seen inFIG. 3. From FIG. 3, it will be noted that the rearward face 76 isspaced from the projection 50 of the groove wall 44 to provide a spacefor the chocks 64, with the center of the face 76 being generally inalignment with the center of the projection 50.

Referring to FIG. 3, it will be noted that the face 76 is configured toprovide shoulder areas 78, each of which is provided with three notches80 (designated 80a, 80b and 80c in FIG. 3) defining curved bearingsurfaces engageable by the chocks 64. As shown in the drawings, thesurface of each shoulder area, within which the notches 80 are provided,lies in a plane which is inclined relative to the forward or left-handface of the lip 68 ofthe ring so that, although the notches 80 are ofidentical size and depth relative to the face .76 of the ring, theirbearing surfaces are spaced different distances from the face of thelip. Ac-

cordingly, a chock of given dimension will space the face 76 of the ringdifferent distances from the projection.50 of the groovedepending uponwhich notch it occupies; and, thus, the compressive force on the gasket,as caused by the axial locationof the ring 62, can be varied dependingupon which notch is occupied.

It is contemplated that a plurality of shoulder areas 78 be provided onthe ring 62 in circumferentially spaced relation to one another (FIG.7), and that each will cooperate with a chock 64. For example, in avalve having a flow passageway diameter of sixteen inches, twellve suchareas may be provided, each spaced 30 circumferentially from an adjacentarea.

Adjacent each shoulder area 78, the face 76 of the ring is indented, asat 82, to facilitate insertion of a chock 64 for movementcircumferentially along the ring to a notch 80 of a shoulder area 78.Thus, an indentation 82 is provided for each shoulder area 78. In theillustrated embodiment, the slit 66 is provided at one of theindentations 82 (FIG. 3).

The chocks 64 are similar to those shown and described in copendingUnited States application Ser. No. 170,922 filed Aug. 11, 1971, and areadapted to be placed intermediate the ring 62 and the adjacent wall 44of the groove 38. They are proportioned so that they will bear againstboth the ring and the groove wall so as to maintain the ring a desireddistance from the wall 44 and thereby maintain the ring in a pressureengagement with the gasket 36 so as to effect radial expansion thereof.Thus,the chocks cause the ring to always exert a compr'essiveforce onthe gasket. The degree of force 6 will vary depending upon which notcheach of the chocks occupies. In addition, the chocks are formedeccentrically about their longitudinal axes, which are radially disposedrelative to the flow axis of the valve body, so as to permit theireffective diameter (thickness) to be varied depending upon theirrotative position, thus permitting further adjustment in the compressiveforces which they maintain.

More specifically, a representative chock 64 is illustrated in enlargedform in FIGS. 4 and 5 and includes a generally cylindrical hub 84provided with an upper head 86 and a lower head 88 each of polygonaltransverse cross-sectional configuration. The hub 84 if of circulartransverse cross-sectional configuration '(FIG. 4), although otherconfigurations are possible, and has a radius closely corresponding totheqradius of curvature of the notches 80 so that the hub willconveniently fit into and bear against the basesor bearingsurfaces ofthe notches. In a preferred embodiment, thehubhas a diameter ofapproximately one-fourth inch and the notches have a radius of curvaturewhich is slightly larger than one-eighth inch.

By virtue of their polygonal cross-sectional configuration, the heads 86and 88 define flats 90 which lie in planes parallel to the cylindricalaxis of the hub 84. In the illustrated embodiment, the polygonalconfiguration is octagonal, although other configurations are possible.Both of the heads 86 and 88 are of like config uration and size so thateach flat of each headlies in the same plane as a flat of the oppositehead. In the assembled valve, the hub of each chock bears against thebearing surface of a notch 80 while a flat 90 of each head 86 and 88bears against the groove wall 44 on op posite sides of the projection50. Thus, the effective width of thechock for purposes of spacing theretaining ring 62 from the wall 44 is the distance between the planewithin which lie the flats 90in engagement with the groove wall 44 and aparallel plane tangent to the diametrically opposite surface of the hub84.

As best seen in FIG.4, the geometric centers92 of the heads 86 and 88are displaced from the cylindrical axis 94 of the hub 84 along a lineperpendicular to an opposed pair of flats. 90. Thus, the planes definedby certain pairs. of flats 90 are spaced from the diametrically oppositecylindrical surface of the hub 84 a differentdistance than are otherplanes. In the illustrated embodiment, these different distances aredesignated a through e, and it will be noted that there are thus fivedifferent spacings available. If the geometric centers of the heads arespaced from the cylindrical axis of the hub along a line notperpendicular to a flat 90 of anoctagonal head, and along a line notpassingthrough a corner, i.e., not passing through a line formed atthejuncture of two flats 90, there will be seven different spacings. In theillustrated embodiment, the head 86is provided with-a slot 96 in itsupper surface transverse to the cylindrical axis 94 of the hub toreccivethe end of a screwdriver so as to facilitate rotation of thecheek. One end of the slot is fanned or notched, as at 98, to indicatethat the flat 90 adjacent thereto provides the minimum effective widthof the chock whenin engagement with the wall 44 of the groove 38.

In the assembly of the embodiment of the butterfly valve 10 illustrated.in FIGS. 1-7, assuming all initial machining has been accomplished, thegasket 36 is inserted into the groove 38 in abutting relation to thewall 42 of the groove with the flange 54 of the gasket in the undercut46. The retaining ring 62 is then collapsed radially as, for example, asshown in FIG. 7 to reduce its diameter, placed within the groove 38adjacent the gasket, and restored to its original shape. The ring 62 maybe merely collapsed radially to reduce its diameter. Depending upon thedimensional relationship between the gasket and the ring 62, the flange56 of the gasket may be in radial compression, but an annular space willexist intermediate the ring 62 and the opposite wall 44 of the groove.At this point, therefore, the gasket 36 will not be in axialcompression. A suitable tool, such as a screwdriver, may then beinserted between the groove wall 44 and the ring adjacent to theindentations 82 to wedge the ring toward the gasket, thereby enlargingthe gap between the ring and the wall 44 and placing the gaskettemporarily in compression.

Chocks 64 are then inserted between the ring and the 1 adjacent groovewall 44 at each indentation 82 and then successively moved or wedgedcircumferentially until thehub 84 of each resides in and bears againstthe base surface of that notch'80a which is closest to the gasket 36,with a portion of each of the heads 86 and 88 disposed on opposite sidesof the end face 76 of the ring, and with a flat 90 of each head bearingagainst the wall 44 above and below the projection 50. The rearward orright-hand face 76 of the ring and the projection 50 thus maintain eachchock against movement longitudinally of its axis.

When the chocks are-positioned with the hubs 84 resting in and partiallyconfined by the semicircular notches, they can be rotated about thecylindrical axes of the hubs by means of a screwdriver or similar toolinserted into the slots 96, these axes being stationary relative to thering 62. Such rotation will bring different flats 90 of the chocks tobear, against the groove wall 44 and thus further vary the compressiveforce which the chocks are capable of maintaining against the segments.6

The proper or desirable degree of compression of the gasket isdetermined empirically by connecting the valve inlet to a source offluid under pressure with the valve disc 28 in the closed position andthen checking the outlet side of the valve disc for leakage. This may bedone by closing the valve, disposing the valve body with the flow axisvertically oriented and with the valve disc 28 horizontally disposed,partially filling the valve body above the disc 28 with water, andconnecting the valve body below the disc to a source of air underpressure. Bubbles passing upwardly through the water will indicate thepresence of a leak.

When placing the chocks 64 in the space between the segments and groovewall 44, it is preferable to first place a chock in each of the notches80a nearest the gasket 36 (the lowermost notch in FIG. 3) and with theflat 90 the minimum distance a from the surface of the hub in contactwith the wall 44, i.e., with the flat 90 adjacent the fanned end 98 ofthe slot 96 in engagement with the groove wall. If such an arrangementproduces leakage at certain portions of the periphery of the valve disc,the chocks adjacent such portions are rotated to successively bring theflats which are a distance b, c, d, and e from the opposed surface ofthe hub into contact with the wall 44, thereby moving or camming thering axially in the direction of the gasket 36 and compressing same soas to move the valve seat 34 radially inwardly. If further compressionis necessary, the appropriate chock (or chocks) is rotated until theflat a distance a from the opposite surface of the hub is again broughtinto contact with the wall 44, and the chock is moved to the nextsucceeding notch 80b or 800 as the case may be and rotation begun againuntil the resulting compression produces the necessary radial expansionof the gasket.

In a preferred embodiment, movement of a chock from one notch 80 to anadjacent notch maintains a difference in axial displacement of the ring62 of 0.04 inch if the same flat of the chock is in engagement with thegroove wall 44. In addition, rotation of the chock illustrated in FIG. 4will produce a total axial displacement of approximately 0.034 inch infour increments.

While a specific embodiment of the invention has been shown anddescribed, a number of variations thereof are possible. For example, thenotches 80 can be provided in a second ring disposed adjacent the groovewall 44, the chocks being thereby interposed between two rings.Likewise, while the location of the notches 80' conveniently locate thechocks to assure that pressure will be applied uniformly to the gasket,such notches could in some instances be dispensed with or could be otherthan a curved configuration to .coact with a hub having other than acylindrical surface. Also, additional sets of notches could be provided.In some circumstances, the chocks could be of uniform cross-sectionalconfiguration from one end to the other so as not to include a hub, withthe spacing between opposed sets offaces being varied to provide thedesired variation incident to rotation. If a sufficient number ofnotches were provided, the added adjustment achieved by rotation of thechocks may not be required. Finally, and with reference to FIG. 2, thehead 88 of the chock 64 could be of circular rather than polygonalconfiguration and serve merely as a retainer, with the head 86 bearingthe load.

The ring 62 thus provided is of single piece construction and, inconjunction with the chocks'64, applies a uniform axially directed forceto the gasket 36 to effect its compression. Depending upon itsdimensions relative to the flange 56 of the gasket 36, it may exert aradially directed force on the flange to securely hold the ring andgasket in place. However, even when such-radially directed forces arenot exerted, the ring resists any tendency for the lip 68'to be liftedoff the inner surface of the flange 56 as might occur with very shortsegments combining to form the ring. This is due to the fact that thechocks 64 prevent axial movement of the entire ring as a unit away fromthe gasket. The single piece construction of the ring also preventstipping or rocking of any given portion effective to lift the lip 68since such tipping or rocking would necessarily be accompanied by anaxial movement of a remote portion of the ring, which axial movement isprevented by the chocks 64.

There is illustrated in FIGS. 8 and 9 alternate embodiments 62a and 62b,respectively, of the ring 62 which, it is believed, would performsatisfactorily under certain circumstances. The ring 62a of FIG. 8 isidentical in cross-sectional configuration to the ring 62 but, ratherthan being in the form of a single piece, is formed of two semi-annularsegments or portions and 102 which abut at V-shaped cuts 104. Theadditional cut facilitates displacement of portions of the ring topermit its insertion into the groove of the valve body. It iscontemplated that the ring 62a be dimensioned so that its lip 68 willplace the flange 56 of the gasket 36 in radial compression and the ringin compression as .well.

It will be appreciated that the arcuate length of the segments 100 and102 is such that any tendency for one of the segments, such as thesegment 102, to rock, as about an axis indicatedby the line 106, wouldtend to cause the ends of the segment at the cuts 104 to move axiallyand that this movement would be resisted by frictional forces at thecuts 104 as well as by the checks bearing against the face of thesegment adjacent such cuts. The interlocking of the segments at theV-shaped cuts insures that the circular configuration of the ring willbe maintained.

In the embodiment of FIG. 9, the ring 62b is comprised of three arcuatesegments 108, 110 and 112, each of which is approximately 120 in lengthcircumferentially. The ends of the segments abut at V-shaped cuts 114.It is contemplated that the ring 62b be identical in cross-sectionalconfiguration to the ring 62 and that it is dimensioned so that its lip68 will place the flange 56 of the gasket 36 in radial compression andthe ring in compression as well. The additional cuts facilitatedisplacement of portions of the ring to permit its insertion into thegroove of the valve body.

Aswith the segment 102, the arcuate length of the segments 108, 110 or1l2'is such that any tendency for one of the segments to rock as, forexample, any tendency for the segment 112 to rock about the axis 116,would tend to cause the ends of the segment at the cuts 114 to moveaxially; and this movement will be resisted by frictional forces at thecuts as well as by the chocks bearing against the face of the segmentadjacent the cuts. Again, the interlocking of the segments at the V-shaped cuts insures that the circular configuration will be maintained.1 a

It is believed preferable that each of the segments defining. the ring62 has a sufficient arcuate length that tipping or rocking of thesegment sufficient to lift the lip 68 of the ring off the flange 56 ofthe gasket would be possible onlyin conjunction with a significantamountof axial movement of the ends of the ring, which axial movementwould be precluded by the checks 64. The length of the are required toachieve this condition will depend to some extent upon the degree oflift that can be tolerated, but arc lengths of 120 are believedacceptable. It should be understood, of course, that all of the segmentsneed not be the same length. For example, one segment may have an arclength of 120 and a second segment have an arc length of 240. Also. itis the effective arc length which is significant. Thus, two or moresegments interconnected at their ends so as to function as a singlepiece might prove satisfactory even though each segment by itself mightbe of insufficient length if not so interconnected. Such interconnectionis achieved in the principal embodiment by forming the entire ring 62 asa single piece, but it might also be achieved by interlocking shortersegments at their ends by means of suitably contoured mating endsurfaces which would prevent relative axial movement of adjacent ends.Thus, one

end of each segment might be provided with a projection or pin to bereceived in a slot or opening in the end of an adjacent segment.

Various features of the invention are set forth in the following claims.

What is claimed is:

l. A butterfly valve body comprising a valve body defining a fluid flowpassageway and having an annular groove therein defined bya baseencircling the flow axis of said passageway an d first and secondopposed groove walls extending from said base in the direction of theflow axis of said passageway,

an annular gasket defining a.valve disc seat disposed in said annulargroove and projecting radially into said fluid flow passageway, whichgasket has first and second opposite surfaces with said first surfacelying in engagement with said first groove *wall,

said gasket being formed of a resilient material capable of expandingradially when subjected to forces having components extending inadirection parallel to the flow axis of said passageway,

said gasket being proportioned so as to provide an annular spaceintermediate a portion of said gasket and said second groove wall andincluding an annular flange located within said space resting on saidgroove base, i an annular retaining ring disposed within said annularspace having one surface in engagementwith said second gasket surfaceand the: radially inward surface of said annular flange, said retainingring having a-normal outer diameter greater than the diameter of saidfluid flow passageway adjacent said groove and said retaining ring beingsplit to provide a discontinuityat a single point which permits thedisplacement of the end portions of said ring relative to each otheratsaid split so as to enable said ring to be collapsed for insertion intosaid annular space and subsequently returned to a planar orientation incontact with said gasket second surface, and means for urging said ringaxially into pressure engagement with said gasket to effect radialexpansion thereof. i 2. A butterfly valve body in accordance with claim1, wherein. said one groove wall is provided with a ledge overhangingthe base of said groove,=wherein said :gasketis provided with anoppositely directed annular flange which lies in contact with said ledgeof said groove wall. i

3. A butterfly valve body in accordancewith claim l wherein said annularretaining ring is dimensioned so that the surface thereof which lies inengagement with I the radially inward surface of said annular flange hasa diameter larger than said flange surface and places said flange inradially outward compression.

4. A butterfly valve body in accordancewith claim 8 wherein said annularretaining ring has its outermost diameter less than the diameter of saidgroove base so as to provide an annular gap between said retaining ringand said groove base about the circumference thereof.

5. -A butterfly valve body in accordance with claim--1 wherein the endportions of said ring at the location of said split are interlocked witheach other to prevent relative radial movement therebetween.

6. A butterfly valve body in accordance withclaim 5 wherein saidannular'retaining ring at the location of i from said one surface andsaid second groove wall, and wherein said urging means includes aplurality of chocks disposed in said gap.

8. A butterfly valve body in accordance with claim 7 wherein each ofsaid chocks includes a polygonal head at each end of a generallycylindrical central portion, said heads being wider than the diameter ofsaid central portion and having flat faces lying in common planesparallel to the cylindrical axis of said central portion, the geometriccenter of each head being displaced from the axis of said cylindricalportion, said cylindrical surface of said central portion and a pair ofthe flat faces engaging said opposite surface of said retaining ring andsaid second groove wall, one of said retaining ring and said secondgroovewall including projecting means which protrudes into the spacebetween said heads to restrain said chocks against radial movement.

9. A butterfly valve body in accordance with claim 8 wherein the axes ofrotation of each of said plurality of chocks lies in a planesubstantially perpendicular to the flow axis of said valve body.

10. A butterfly valve body comprising a valve body defining a fluid flowpassageway and having an annular groove therein defined by a baseencircling the flow axis of said passageway and first and second opposedgroove walls extending from said base in the direction of the flow axisof said passageway, I

an annular gasket defining a valve disc seat disposed in saidannulargroove and projecting radially into said fluid flow passageway,which gasket has first and second opposite surfaces with said firstsurface lying in engagement with said first groove wall,

said gasket being formed of a resilient material capable of expandingradially when subjected to forces having compoennts extending in adirection parallel to the flow axis of said passageway,

said gasket being proportioned so as to provide an annular spaceintermediate a portion of said gasket and said second groove wall andincluding an annular flange located within said space resting on saidgroove base,

an annular retaining ring disposed within said annular space having onesurface in engagement with said second gasket surface and the radiallyinward surface of said annular flange,

said retaining ring being split into no more than three arcuateportions, adjacent ends of said split ring portions being interlockedwith each other to prevent relative radial movement thereof, and

means for uring said retaining ring axially into pressure engagementwith said gasket to effect radial expansion thereof.

11. A butterfly valve body in accordance with claim 10, wherein said onegroove wall is provided with a ledge overhanging the base of saidgroove, wherein said gasket is provided with an oppositely directedannular flange which lies in contact with said ledge of said groovewall.

12. A butterfly valve body in accordance with claim 10 wherein saidannular retaining ring is formed from a pair of arcuate ring sectionseach of which has an arcuate length of about 180.

13. A butterfly valve body in accordance with claim 10 wherein saidannular retaining ring is split at at least two circumferentially spacedpoints to divide said ring I 12 into separate portions, each of whichportions has an arcuate length of at least about 14. A butterfly valvebody in accordance with claim 10 wherein said interlocking end portionsof said annular retaining ring are formed respectively witha generallyV-shaped notch and with a mating V-shaped projection.

15. A butterfly valve body in accordance .with claim 10 wherein saidannular retaining ring is dimensioned so that the surface thereof whichlies in engagement with the radially inward surface of said annularflange has a diameter larger than said flange surface and places saidflange in radially outward compression.

16. A butterfly valve body in accordance with claim 15 wherein saidannular retaining ring has its outermost diameter less than the diameterof said groove base so as to provide an annular gap between saidretaining ring and said groove base about the circumference thereof.

17. A butterfly valve body in accordance with claim 10 wherein thecross'section of said retaining ring is such to provide a gap betweenthe surface thereof opposite from said one surface and said secondgroove wall, and wherein said urging means includes a plurality ofchocks disposed in said gap.

18. A butterfly valve body in accordance with claim 17 wherein each ofsaid chocks includes a polygonal head at each end of a generallycylindrical central portion, said heads being wider than the diameter ofsaid central portion and having flat faces lying in common planesparallel to the cylindrical axis of said central portion, the geometriccenter of each head being displaced from the axis of said cylindricalcentral portion, said cylindrical surface of said central portion and apair of the flat faces engaging said opposite surface of said annularretaining ring and said second groove wall, one of said annularretaining ring and said second groove wall including projecting meanswhich protrudes into the space between said heads to restrain saidchocks against radial movement.

19. A butterfly valve body comprising a valve body defining a fluid flowpassageway and having an annular groove therein defined by a baseencircling the flow axis of said passageway and first and second opposedgroove walls extending from said base in the direction of the flow axisof said passageway, an annular gasket defining a valve disc seatdisposed in said annular groove and projecting radially into said fluidflow passageway, said gasket having first and second opposite surfaceswith said first surface lying in engagement with said first groove wall,said gasket being formed of a resilient material capable of expandingradially when subjected to a compressive load, said gasket beingproportioned so as to provide an annular space intermediate a portion ofsaid gasket and said second groove wall and including an annular flangelocated within said space resting on said groove base, and an annularretaining ring disposed within said annular space having one surface inengagement with said second gasket surface and the radially inwardsurface of said gasket annular flange, said retaining ring beingintegral except for a split at a single location which permits saidretaining ring to be collapsed for installation into said valve body,said split ends of said ring being interlocked with each other toprevent relative radial movement thereof.

20. A butterfly valve body in accordance with claim 19 wherein the outerdiameter of said retaining ring is greater than the inner diameter ofsaid gasket annular flange so that said retaining ring is in pressureengagement with said gasket and applies a compressive load thereto whicheffects radial expansion thereof.

' UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,774, 880 Dated November .37. 1973 I t r-( Carter C. Crookham et a1.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column'l, line 16, "interchanging" should be I interengaging--. Column2,line 41, "vale" should be --valve- Column 5, line '4 "twellve" should be-tuelve-. Column 11, line 37; Claim 10, "compoennte" should be I-'-components- I I I V Column'll, line 52, Claim 10, "uring" should beSigned 1 sealed this 11th day of June 1971+;

(SEAL) Attest:

EDWARD M.FLETCHER,JR. V G. MARSHALL DANN Attesting Officer Commissionerof Patents UsCOMM-Dg 6 0376-P69 r us. oovimnlnrr nlpmlo orrlc: II"o-nl-sn,

FORM PO-105O (10-69)

1. A butterfly valve body comprising a valve body defining a fluid flowpassageway and having an annular groove therein defined by a baseencircling the flow axis of said passageway and first and second opposedgroove walls extending from said base in the direction of the flow axisof said passageway, an annular gasket defining a valve disc seatdisposed in said annular groove and projecting radially into said fluidflow passageway, which gasket has first and second opposite surfaceswith said first surface lying in engagement with said first groove wall,said gasket being formed of a resilient material capable of expandingradially when subjected to forces having components extending in adirection parallel to the flow axis of said passageway, said gasketbeing proportioned so as to provide an annular space intermediate aportion of said gasket and said second groove wall and including anannular flange located within said space resting on said groove base, anannular retaining ring disposed within said annular space having onesurface in engagement with said second gasket surface and the radiallyinward surface of said annular flange, said retaining ring having anormal outer diameter greater than the diameter of said fluid flowpassageway adjacent said groove and said retaining ring being split toprovide a discontinuity at a single point which permits the displacementof the end portions of said ring relative to each other at said split soas to enable said ring to be collapsed for insertion into said annularspace and subsequently returned to a planar orientation in contact withsaid gasket second surface, and means for urging said ring axially intopressure engagement with said gasket to effect radial expansion thereof.2. A butterfly valve body in accordance with claim 1, wherein said onegroove wall is provided with a ledge overhanging the base of saidgroove, wherein said gasket is provided with an oppositely directedannular flange which lies in contact with said ledge of said groovewall.
 3. A butterfly valve body in accordance with claim 1 wherein saidannular retaining ring is dimensioned so that the surface thereof whichlies in engagement with the radially inward surface of said annularflange has a diameter larger than said flange surface and places saidflange in radially outward compression.
 4. A butterfly valve body inaccordance with claim 3 wherein said annular retaining ring has itsoutermost diameter less than the diameter of said groove base so as toprovide an annular gap between said retaining ring and said groove baseabout the circumference thereof.
 5. A butterfly valve body in accordancewith claim 1 wherein the end portions of said ring at the location ofsaid split are interlocked with each other to prevent relative radialmovement therebetween.
 6. A butterfly valve body in accordance withclaim 5 wherein said annular retaining ring at the location of saidsplit has one end portion formed with a generally V-shaped notch and theother eNd portion formed with a mating V-shaped projection.
 7. Abutterfly valve body in accordance with claim 1 wherein the crosssection of said retaining ring is such to provide a gap between thesurface thereof opposite from said one surface and said second groovewall, and wherein said urging means includes a plurality of chocksdisposed in said gap.
 8. A butterfly valve body in accordance with claim7 wherein each of said chocks includes a polygonal head at each end of agenerally cylindrical central portion, said heads being wider than thediameter of said central portion and having flat faces lying in commonplanes parallel to the cylindrical axis of said central portion, thegeometric center of each head being displaced from the axis of saidcylindrical portion, said cylindrical surface of said central portionand a pair of the flat faces engaging said opposite surface of saidretaining ring and said second groove wall, one of said retaining ringand said second groove wall including projecting means which protrudesinto the space between said heads to restrain said chocks against radialmovement.
 9. A butterfly valve body in accordance with claim 8 whereinthe axes of rotation of each of said plurality of chocks lies in a planesubstantially perpendicular to the flow axis of said valve body.
 10. Abutterfly valve body comprising a valve body defining a fluid flowpassageway and having an annular groove therein defined by a baseencircling the flow axis of said passageway and first and second opposedgroove walls extending from said base in the direction of the flow axisof said passageway, an annular gasket defining a valve disc seatdisposed in said annular groove and projecting radially into said fluidflow passageway, which gasket has first and second opposite surfaceswith said first surface lying in engagement with said first groove wall,said gasket being formed of a resilient material capable of expandingradially when subjected to forces having compoennts extending in adirection parallel to the flow axis of said passageway, said gasketbeing proportioned so as to provide an annular space intermediate aportion of said gasket and said second groove wall and including anannular flange located within said space resting on said groove base, anannular retaining ring disposed within said annular space having onesurface in engagement with said second gasket surface and the radiallyinward surface of said annular flange, said retaining ring being splitinto no more than three arcuate portions, adjacent ends of said splitring portions being interlocked with each other to prevent relativeradial movement thereof, and means for uring said retaining ring axiallyinto pressure engagement with said gasket to effect radial expansionthereof.
 11. A butterfly valve body in accordance with claim 10, whereinsaid one groove wall is provided with a ledge overhanging the base ofsaid groove, wherein said gasket is provided with an oppositely directedannular flange which lies in contact with said ledge of said groovewall.
 12. A butterfly valve body in accordance with claim 10 whereinsaid annular retaining ring is formed from a pair of arcuate ringsections each of which has an arcuate length of about 180*.
 13. Abutterfly valve body in accordance with claim 10 wherein said annularretaining ring is split at at least two circumferentially spaced pointsto divide said ring into separate portions, each of which portions hasan arcuate length of at least about 120*.
 14. A butterfly valve body inaccordance with claim 10 wherein said interlocking end portions of saidannular retaining ring are formed respectively with a generally V-shapednotch and with a mating V-shaped projection.
 15. A butterfly valve bodyin accordance with claim 10 wherein said annular retaining ring isdimensioned so that the surface thereof which lies in engagement withthe radially inward surface of said annular flange has a diameter laRgerthan said flange surface and places said flange in radially outwardcompression.
 16. A butterfly valve body in accordance with claim 15wherein said annular retaining ring has its outermost diameter less thanthe diameter of said groove base so as to provide an annular gap betweensaid retaining ring and said groove base about the circumferencethereof.
 17. A butterfly valve body in accordance with claim 10 whereinthe cross section of said retaining ring is such to provide a gapbetween the surface thereof opposite from said one surface and saidsecond groove wall, and wherein said urging means includes a pluralityof chocks disposed in said gap.
 18. A butterfly valve body in accordancewith claim 17 wherein each of said chocks includes a polygonal head ateach end of a generally cylindrical central portion, said heads beingwider than the diameter of said central portion and having flat faceslying in common planes parallel to the cylindrical axis of said centralportion, the geometric center of each head being displaced from the axisof said cylindrical central portion, said cylindrical surface of saidcentral portion and a pair of the flat faces engaging said oppositesurface of said annular retaining ring and said second groove wall, oneof said annular retaining ring and said second groove wall includingprojecting means which protrudes into the space between said heads torestrain said chocks against radial movement.
 19. A butterfly valve bodycomprising a valve body defining a fluid flow passageway and having anannular groove therein defined by a base encircling the flow axis ofsaid passageway and first and second opposed groove walls extending fromsaid base in the direction of the flow axis of said passageway, anannular gasket defining a valve disc seat disposed in said annulargroove and projecting radially into said fluid flow passageway, saidgasket having first and second opposite surfaces with said first surfacelying in engagement with said first groove wall, said gasket beingformed of a resilient material capable of expanding radially whensubjected to a compressive load, said gasket being proportioned so as toprovide an annular space intermediate a portion of said gasket and saidsecond groove wall and including an annular flange located within saidspace resting on said groove base, and an annular retaining ringdisposed within said annular space having one surface in engagement withsaid second gasket surface and the radially inward surface of saidgasket annular flange, said retaining ring being integral except for asplit at a single location which permits said retaining ring to becollapsed for installation into said valve body, said split ends of saidring being interlocked with each other to prevent relative radialmovement thereof.
 20. A butterfly valve body in accordance with claim 19wherein the outer diameter of said retaining ring is greater than theinner diameter of said gasket annular flange so that said retaining ringis in pressure engagement with said gasket and applies a compressiveload thereto which effects radial expansion thereof.